Have you already started on this concept? Myself and our team are working on some of the ideas you listed for an upcoming app (https://itunes.apple.com/us/app/guardian-firewall/id13637963...). It would be great to chat further, if you have interest in working on this concept (e-mail is will.strafach@guardianapp.com).

Designing a reasonably secure and reliable mobile VPN has been a very difficult challenge to get right. If you look at existing mobile VPNs through a tool such as Charles Proxy or Burp, you will see that none of them really appear to be designed very well. There are many unsolved technical problems with managing and scaling such services, likely avoided by existing providers due to how easy the issues are to mask. That said, Cloudflare’s cautious approach with Warp gives me some confidenxe that they really are trying to do this right.